1. Field of the Invention
The invention relates to a miniaturized terminal fitting.
2. Description of the Related Art
A known miniaturized terminal fitting is disclosed in Japanese Unexamined Patent Publication No. 8-306420. This terminal has a rectangular tubular portion with a resilient contact piece inside. A male tab can be inserted into the rectangular tubular portion, and thus can be brought resiliently into contact with the resilient contact piece. The resilient contact piece is comprised of a curved portion that extends back from the front end of the bottom wall of the rectangular tubular portion and a contact portion that extends back from the curved portion substantially parallel to the bottom wall from the curved portion. The contact portion is located on an entrance path of the male tab and is displaced downward substantially about the curved portion when the male tab is connected. As a result, the radius of curvature of the curved portion is reduced, and a specified contact pressure can be ensured between the contact portion and the male tab by this resiliently restoring force.
There are advantages to reducing the height of a terminal fitting that has such a resilient contact piece. A height reduction of such a terminal fitting could be achieved by reducing the radius of curvature of the curved portion of the resilient contact piece. However, stress disadvantageously concentrates on a curved portion that has had its radius of curvature reduced.
In view of the above, an object of the present invention is to make an entire terminal fitting smaller while avoiding concentration of a stress on a resilient contact piece.
The invention is directed to a terminal fitting that has a cantilever-shaped resilient contact piece with can be brought into contact with a tab of a mating terminal. The resilient contact piece comprises a curved portion folded back at an end of a support plate. A touching portion extends further from an extending end of the curved portion and is held at least partly in contact with the support plate. A contact portion extends further from an extending end of the touching portion and is spaced from the support plate. The contact portion can be brought into contact with the tab.
The contact portion is displaced substantially about the touching portion and toward the support plate when the resilient contact piece is connected with the tab. More particularly the displacement of the contact portion primarily involves a deformation of a section that connects the touching portion and the contact portion. A contact pressure can be ensured between the resilient contact piece and the tab by the resilient restoring force of the resilient contact piece. The curved portion is not deformed resiliently when the contact portion is displaced, and hence there is no possibility of concentrating a stress on the curved portion. Accordingly, the height of the terminal fitting can be reduced without creating a concentration of stress on the curved portion.
The touching portion preferably is held substantially in close contact with the support plate portion over its entire length along its extending direction.
The contact portion may be displaced about the extending end of the touching portion while resiliently deforming the extending end of the touching portion.
An end area of the support plate opposed to both the curved portion and the touching portion preferably is deformed resiliently when the touching portion is deformed. Thus, concentration of a stress on the touching portion can be moderated.
One end of the terminal fitting preferably defines a rectangular tube that comprises the support plate and two opposed side plates that extend continuously up from opposite side edges of the supporting plate. Slits are formed at the end of the rectangular tube between the support plate and the side plates. The slits make an end area of the support plate resiliently deformable.
The side plates at the opposite sides of the curved portion and the touching portion protect the curved portion and the touching portion from interference of external matter.
The resiliently deformable area is formed at least partly by causing a portion of the support plate to project from side walls without providing the side walls at the opposite sides of the curved portion and the touching portion.
The resilient deformable area of the support plate extends from the end of the support plate to a supporting point for the displacement of the contact portion. The supporting point is located in the touching portion.
Since the supporting points for the resilient deformation of the support plate and for the displacement of the contact portion are at the same position. Thus, the touching portion does not separate from the support plate and, the curved portion does not undergo a resilient deformation.
The contact portion may comprise an embossment for contacting the tab. A wall opposed to the support plate also may comprise an embossment. The embossments of the wall and the contact portion preferably are spaced by a distance smaller than the width of the tab to be inserted therebetween.
The support plate preferably comprises an auxiliary spring portion that contacts the contact portion when the contact portion is deflected by the contact with the tab. The auxiliary spring portion preferably cantilevers in a direction different from the contact portion.
The projecting distance of the curved portion preferably is less than the projecting distance of the contact portion.
The contact portion preferably comprises an elongated portion that is sloped or angled down to approach the support plate along an extending direction.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.